You probably have a filter set on your iPhone. Fern had this problem once.Look at one of the photos in the photos app on your phone.Tap editIf you're running recent software, click on the icon that is three overlapping circles.Click none.Your photo should look normal.

Phone photos aren't as good as a real camera, but they're not bad. Most everything you see on Facebook was taken with a phone. If your colors were way off there must have been a filter set or there is something wrong with your phone.